import { fileURLToPath } from "node:url";
import { afterEach, describe, expect, it } from "vitest";
import {
	createPiSession,
	type PiSession,
} from "../../../test/fixture/create-pi-session.ts";
import { __test } from "../index.ts";

let session: PiSession | undefined;

afterEach(async () => {
	await session?.dispose();
	session = undefined;
});

describe("context-size contract", () => {
	it("loads through the owned fixture", async () => {
		session = await createPiSession({
			extensionPaths: [fileURLToPath(new URL("../index.ts", import.meta.url))],
		});

		expect(session.errors).toEqual([]);
		expect(session.extensions).toHaveLength(1);
	});

	it("renders the tui view as a bar alone", () => {
		expect(__test.renderThinBar(26)).toBe("━━━───────");
		expect(__test.renderThinBar(null)).toBe("──────────");
	});

	it("spells out the non-tui label with human-readable headroom", () => {
		expect(
			__test.buildPlainLabel({
				tokens: 262_000,
				contextWindow: 1_000_000,
				percent: 26.2,
			}),
		).toBe("context 26% used, 738k left");

		expect(
			__test.buildPlainLabel({
				tokens: null,
				contextWindow: 1_000_000,
				percent: null,
			}),
		).toBe("context unknown");
	});

	it("scales token counts through k and M", () => {
		expect(__test.formatTokens(940)).toBe("940");
		expect(__test.formatTokens(1_180)).toBe("1.2k");
		expect(__test.formatTokens(262_000)).toBe("262k");
		expect(__test.formatTokens(1_618_000)).toBe("1.6M");
		expect(__test.formatTokens(121_527_000)).toBe("122M");
	});
});